Investigation the Effect of Ar-Air plasma Treatment on Separation Performance of Nanofiltration Membrane: Influence of Time, Power and Composition of Plasma

In this study, thin film nanofiltration membranes were modified by using Ar-Air plasma. The effect of plasma time, power and the composition of plasma gases on physico-chemical properties and separation performance of membranes were investigated. The results showed that the plasma treatment caused to increase in membrane surface hydrophilicity considerably. The surface modification of membranes by using plasma treatment led to enhancement of water flux through the membrane obviously. The separation efficiency of membranes due to surface modification was also changed broadly compared to unmodified membrane. The separation efficiency of modified membranes at 35 W and 180 s, 25 W and 120 s, and 15 W and 60 s plasma treatment measured ~30%, 76%-92%  and 77%-89% respectively. The selectivity for un-modified membrane was also measured ~90%. Among all studied membranes, the modified membrane at 50-50 (v/v) Ar-Air plasma, 25 W and 120 s treatment with considerable enhancement of water flux compared to pristine membrane was selected as the optimum sample.